1. Field of the Invention
The present invention relates to power supplies and, more particularly, to a power supply capable of being switched between two different input voltages.
2. Description of the Prior Art
A universal power supply, such as one used to supply a battery charger, may be used irrespective of the voltage standard employed by the country in which the power supply is being used. The United States uses the 110V 60 Hz standard, whereas Europe uses the 230V 50 Hz standard. Often, different countries use different types of electrical plugs. While some universal power supplies may include a switch to allow them to be used with the different standards, most have significant electronic circuitry necessary to cover a wide range of voltages and the circuitry tends to be higher rated and, therefore, more costly. Furthermore, with existing power supplies, it is possible to forget the position of the switch and, therefore, it is possible to apply the wrong voltage to the power supply.
Therefore, there is a need for a universal power supply that automatically configures itself for a voltage corresponding to a given electrical standard.